What is the Air Quality Index?

NEW YORK (WABC) -- The Air Quality Index is a scale used for daily reporting of how clean or polluted the air is, and what health effects might be of concern.

The AQI focuses on what you might experience if exposed within a few hours or days after breathing polluted air.

The Environmental Protection Agency calculates the AQI using 5 major air pollutants regulated by the Clean Air Act:

The AQI runs from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern.

The index is divided into six categories, each corresponding to a different level of health concern.

WATCH | If Canadian wildfires continue, what does that mean for us?

Dr. Robert Laumbach, an air quality expert at Rutgers University, joins 'Eyewitness News Extra Time,' with more on the potential impact of prolonged wildfire conditions in Canada.

An AQI of over 100 triggers an alert for vulnerable groups.

Levels over 300 signal a health emergency and everyone is more likely to be affected.

The air quality in New York City and across the northeast is the worst since record-keeping began in 1999 because of the wildfire smoke from Canada, officials said.

Learn more about the index from the EPA at AirNow.gov.

ALSO READ | New York City air quality reaches dangerous levels due to Canadian wildfire smoke

Smoke from hundreds of wildfires burning north of the border continues to create dangerous air quality conditions across our area. NJ Burkett reports.

----------

* Get Eyewitness News Delivered

* More New York City news

* Send us a news tip

* Download the abc7NY app for breaking news alerts

* Follow us on YouTube

Submit a tip or story idea to Eyewitness News

Have a breaking news tip or an idea for a story we should cover? Send it to Eyewitness News using the form below. If attaching a video or photo, terms of use apply.